A conventional type of pressure sensors having structures that prevent entry of foreign materials has been proposed in, for example, Patent Literature 1. Specifically, a structure has been proposed that includes a pressure detection element placed in a case having a port through which a pressure medium is guided to the pressure detection element.
The port protrudes from the exterior wall of the case. The port has an opening that opens to the lower end of the port and a passageway introducing the pressure medium into the inside of the case through the opening. That is, the port has a structure resembling an umbrella. The upper end of the port is flat, and an opening end that defines the opening is also flat.
The inventors of the present application have found the following. The conventional technique may allow water to be collected when the upper end is exposed to water, since the upper end of the port is flat. The water may flow from the upper end along the exterior wall of the port and freeze into ice. The ice may grow into an icicle, which may block the opening of the port.
Additionally, water tends to remain at the opening end of the opening of the port since the opening end is flat, instead of flowing away from the opening end. The water remaining at the opening end may freeze into ice, which may grow into an icicle. The icicle may block the opening of the port.